import json
import logging
import os
import time
from collections import OrderedDict
from pathlib import Path

logger = logging.getLogger(__name__)


class FeishuDeduplicator:
    def __init__(self, max_size: int = 10000, ttl_seconds: int = 25560, storage_dir: str | None = None):
        self._cache: OrderedDict[str, float] = OrderedDict()
        self._max_size = max_size
        self._ttl = ttl_seconds
        self._storage_dir = storage_dir
        self._flush_pending: set[str] = set()

    def is_duplicate(self, msg_id: str) -> bool:
        if not msg_id:
            return False

        now = time.monotonic()
        self._evict_expired(now)

        if msg_id in self._cache:
            return True

        self._cache[msg_id] = now
        while len(self._cache) > self._max_size:
            self._cache.popitem(last=False)

        return False

    def record(self, msg_id: str) -> None:
        if not msg_id:
            return
        now = time.monotonic()
        self._evict_expired(now)
        self._cache[msg_id] = now
        while len(self._cache) > self._max_size:
            self._cache.popitem(last=False)

    def finalize(self, msg_id: str) -> None:
        if not msg_id:
            return
        self._flush_pending.add(msg_id)
        self._persist()

    def _persist(self) -> None:
        if not self._storage_dir:
            return
        try:
            store_path = Path(self._storage_dir) / "feishu_dedup.json"
            store_path.parent.mkdir(parents=True, exist_ok=True)
            ids = list(self._flush_pending)
            store_path.write_text(json.dumps(ids, ensure_ascii=False), encoding="utf-8")
        except OSError:
            logger.warning("Failed to persist dedup state", exc_info=True)

    def _evict_expired(self, now: float):
        expired = [k for k, v in self._cache.items() if now - v > self._ttl]
        for k in expired:
            del self._cache[k]

    def warmup(self, stored_ids: set[str] | None = None) -> None:
        now = time.monotonic()
        if stored_ids:
            for msg_id in stored_ids:
                self._cache[msg_id] = now
                self._flush_pending.add(msg_id)
        elif self._storage_dir:
            store_path = Path(self._storage_dir) / "feishu_dedup.json"
            if store_path.exists():
                try:
                    content = store_path.read_text(encoding="utf-8")
                    ids = json.loads(content)
                    for msg_id in ids:
                        if now - self._ttl < now:
                            self._cache[msg_id] = now
                            self._flush_pending.add(msg_id)
                    # 清理超过 TTL 的持久化条目
                    self._persist()
                except (OSError, json.JSONDecodeError):
                    logger.warning("Failed to load dedup state", exc_info=True)

    def reset(self):
        self._cache.clear()
        self._flush_pending.clear()
        if self._storage_dir:
            store_path = Path(self._storage_dir) / "feishu_dedup.json"
            try:
                if store_path.exists():
                    os.remove(store_path)
            except OSError:
                pass


_deduplicators: dict[str, FeishuDeduplicator] = {}


def get_deduplicator(account_id: str) -> FeishuDeduplicator:
    if account_id not in _deduplicators:
        _deduplicators[account_id] = FeishuDeduplicator()
    return _deduplicators[account_id]